Hi I'm a bit of a novice and don't know alot about bikes. I have a GT zum s2 that I use to get to work and back and I want higher gears. I've got an 8 speed system with a triple chainset at the front think the largest 48 teeth and I've never used the small one. Is a new chain set the best option? Will any Triple chainset design for 8 speeds fit? And would I need anything else?